s = input()
s = input()

R_num = s.count("R")
print(s[:R_num].count("W")) s = input() s input() input s = input() s input() input R_num = s.count("R") R_num s.count("R") s.count s count "R" print(s[:R_num].count("W")) print s[:R_num].count("W") [:R_num].count [:R_num] s :R_num R_num count "W" s = input() input() s R_num = s.count("R") s.count("R") R_num s = input() input() s
s = input()
s = input()

R_num = s.count("R")
print(s[:R_num].count("W"))
